In the last period we have worked on PRKN, PINK, APP, PS1, PS2, PRNP, PGRN and ATXN2/3 mutations in varied neurological diseases. We have continued our work in spinocerebellar ataxias by establishing the frequency of SCA15 mutations identified by us in a large cohort and by follow up of as yet unpublished SCA loci identified by us using autozygosity mapping. In addition we continue to work with our collaborators at NINDS and NHGRI to establish which of our patients have LRRK2 mutations and can be enrolled in our collaborative study following these patients and their as yet unaffected family members prospectively. In addition this year we have performed an assessment of APOE variability in Parkinson's disease, as all previous studies provided somewhat unclear results. This work involved analysis of the common coding variants (epsilon types) in APOE in a very large cohort of PD patients (this work is currently under review). We have also performed an assessment of candidate loci for recessive ataxia in a series of patients from Tunisia who have ataxia. This work allows us to parse such families into those with known mutations, and those that should be prioritized for further genetic work aimed at finding new genetic causes of disease.